This circuit for UHF between 800 and 1 000 MHz was found in an American documentation from the 90's. The integrated circuit is from that time, uncommon today.
This traditional configuration is from a 1976 publication, showing that nothing has changed since...
This circuit is temperature stabilized. Modern equivalent transistors can be used, and the power...
This circuit was found in a 90s Popular Electronics. The sensors can be common speakers that reach...